Tap.



PATENTED JULY 17, 1906.

D. J. GRACE.

TAP. APPLICATION FILED AUG. 17. 1905.

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UNITED STATES I DANIEL J. GRACE, OF PITTSBURG, KANSAS.

TAP.

Specification of Letters Patent.

Eatentec. Jury 1'71, 1906.

Application filed August 1'7, 1905. Serial No. 274,570.

To all whom, it may concern.-

Beit known that I, DANIEL J. Gimme, a citizen of the United States, residing at Pittsburg, in the county of Crawford and State of Kansas, have invented certain new and useful Improvements in Taps, of which thefollowing is a specification.

This invention relates more particularly to means for threading the walls of stay-bolt openings or the like where tie or stay bolts are employed to connect spaced elements, which elements must be correspondingly threaded in order to receive said bolts.

The principal object is to provide a novel and simple structure by means of which after the threads have been formed in the opening of one sheet the threads can be readily cut in the other, and said threads will, of necessity, correspond to and cooperate with the first threads out, so that a stay-bolt can be properly screwed into position.

The preferred embodiment of the invention is disclosed in the accompanying drawings, wherein- Figure 1 is a side elevation of the tap, the intermediate portion being broken away in order to illustrate the construction on a sufliciently large scale. Fig. 2 is a longitudinal sectional view through the same. Fig. 3 is a view in elevation of the cutting end of the tap. Fig. 4 is a similar view of the opposite end with the wedge removed. Fig. 5 is a view similar to Fig. 1, but showing the wedge in place and the head expanded.

Similar reference-numerals designate corresponding parts in all the figures of the drawlngs.

In the embodiment illustrated a tubular stem 6 is employed, one end of which carries a thread-cutting tap 7, which in the present embodiment is shown as tapered and integral with the stem, though the structure and shape of said tap are not important and may be changed as desired to suit the various conditions of use. The other end of the stem is slotted longitudinally, as shown at 8, three slots being employed in the present embodiment, though this number may be varied as desired. The slotted end constitutes a head which is eXteriorly threaded, as shown at 9, the pitch of the threads 9 corresponding to the pitch of the tap-threads.

The threaded head 9 is laterally eXpansible, and means are provided for expanding the same. This means consists of a wedge-plug 10, which is movable into and out of the slotted end of the stem and is carried by a shank 1 1, extending-longitudinally through the bore of said stem and having the end opposite the block 10 threaded, as shown at 12. Screwed upon this threaded stem is a nut 13, which bears against the end of the stem, said end being preferablyangular in cross-section, as shown at 14, to receive suitable operating means, which may be of any desired character.

In threading the stay-bolt openings of a boiler the top or outer hole is first tapped with any well-known straight tap having a long tail or blank end to guide it, after which the present tap is placed in position through the inner or fire-box side. The nut 13 is then turned to draw the wedge 10 into the stem, so as to expand the head and cause the threads 9 to interfit with the threads formed in the outer opening. Said head thus constitutes a lead or guide, and upon turning the same the tap 7 is bound to form in the walls of the inner opening threads corresponding to the threads already formed in the outer opening. As a result the threads will properly cooperate to receive a staybolt.

It will be apparant from the illustration that this structure is simple and can be readily manufactured.

From the foregoing it is thought that the construction, operation, and many advantages of the herein-described invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape, proportion, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a tap of the character described, the combination with a stem, of a thread-cutting tap carried by the stem, and an eXpansible lead or guide for said tap also carried by the stem.

2. In a tap of the character described, the combination with a stem, of a thread-cutting tap carried by one end of the stem, and an eX- pansible threaded head carried by the other end of the stem and constituting a lead or guide for said tap, and means operating against the interior of the head for expanding the same.

3. In a tap of the character described, the combination with a stem, of a thread-cutting tap carriedby the stem, an expansible lead or guide for said tap also carried by the stem,

"and means for expanding said lead or guide.

, 4. In atap of the character described, the combination with a stem, of a thread-cutting tap carried by one end of the stem, an expansible, exteriorly-threaded head carried by the stem, and means also carried by the stem for laterally expanding the head.

5. In a tap of the character described, the combination With a tubular stem, of a thread.-

panding the head, said means including a shank passing through the stem, and a Wedge cooperating with the head.

6. In a tap of the character described, the combination With a tubular stem having longitudinally-disposed slots in one end, of a tap carried by the unslotted end of the stem, threads located upon the slotted end, a shank extending longitudinally through the stem, a wedge carried by the shank and arranged to engage the slotted end to expand the same, and. means associated With the other end of the shank to move the same longitudinally of the stem.

In testimony whereof I affix my signature in presence of two Witnesses.

DANIEL J. GRACE. Witnesses:

D. F. MOCAFFREY, GEO. A. OAss. 

